We also have done some dyno runs with various filters. There was some lower numbers with the S/H being so small (I like the look) but, the worst was the dropped base. You're cutting cfm into the carb. because apx. half of filter is blocked. It also ran a little,.....lean on fuel, would it be enough to cause problems, I don't know, more intense studies would be needed. I would suggest going with a 12" and not a 14" if room is a problem.
Also, if you're using a K & N type filter, keep it very clean and oiled. We've seen limitations in cfm passing through the filter. I had to increase one pill size because the engine ran lean. They are a great filter if used properly and kept clean. I think people tend to ignore regular maintenance because they are supposed to last 1,000,000 miles. After all, if the filter is plugged up, no air gets through. We ran a car that the owner failed to keep his oiled filter clean, then used a cheap paper filter, the results were amazing for just a filter. He gained 4 hp. That to me proves that mama was right, everything works better,......clean.
On the sprint car, we use the K & N that has one filter per 2 cylinders, so four all together. We now clean them every week, rather than what most sprint teams schedule is, of one time every 4 races. We have not hurt a engine in the last 8 years due to lack of maintenance, and that's the key !
So, keep your filters clean guys.